I was wondering if the different isomers of some substances have different rf values? And if yes, what are the values in the database for?

E.g. is it possible to judge by TLC if Meth or Mephedrone is pure dextro or a racemic mix?

I guess not, as most labs even cannot tell you the isomer ratio.

BTW: Thanks again a lot for these kits. They are such a cheap way to know what you get, and it simply works!!!

For the separation of chiral isomers, you'll need a chirally active stationary phase. Probably needs to be tailored a bit to the specific substance to be separated, surely will be quite expensive.

There are other methods, eg. employing a specific stereoisomer of tartaric acid to form complexes with the isomers of the target substance with different solubilities.

@Pitubo: Ah, thank you very much!